Variations in sediment texture on the northern Monterey Bay National Marine Sanctuary continental shelf
B. D. Edwards
2002, Marine Geology (181) 83-100
The storm-protected continental shelf of Monterey Bay, part of the Monterey Bay National Marine Sanctuary, north-central California, is subject to abundant, episodic sediment input from fluvial sources. North of Monterey Bay, conditions of reduced sediment supply combined with the exposed nature of the shelf provide an effective laboratory for studying...
Differences in Englemann spruce forest biogeochemistry east and west of the Continental Divide in Colorado, USA
H.M. Rueth, Jill Baron
2002, Ecosystems (5) 45-57
We compared Englemann spruce biogeochemical processes in forest stands east and west of the Continental Divide in the Colorado Front Range. The divide forms a natural barrier for air pollutants such that nitrogen (N) emissions from the agricultural and urban areas of the South Platte River Basin are transported via...
Evaluation of Light Detection and Ranging (LIDAR) for measuring river corridor topography
Z.H. Bowen, R.G. Waltermire
2002, Journal of the American Water Resources Association (38) 33-41
LIDAR is relatively new in the commercial market for remote sensing of topography and it is difficult to find objective reporting on the accuracy of LIDAR measurements in an applied context. Accuracy specifications for LIDAR data in published evaluations range from 1 to 2 m root mean square error (RMSEx,y)...
Magnetic fields over active tectonic zones in ocean
Yu. A. Kopytenko, P.M. Serebrianaya, L.V. Nikitina, A.W. Green
2002, Journal of Geodynamics (33) 489-496
The aim of our work is to estimate the electromagnetic effects that can be detected in the submarine zones with hydrothermal activity. It is known that meso-scale flows appear in the regions over underwater volcanoes or hot rocks. Their origin is connected with heat flux and hot jets released from...
Riparian vegetation response to altered disturbance and stress regimes
P.B. Shafroth, J.C. Stromberg, D.T. Patten
2002, Ecological Applications (12) 107-123
Management of terrestrial carbon fluxes is being proposed as a means of increasing the amount of carbon sequestered in the terrestrial biosphere. This approach is generally viewed only as an interim strategy for the coming decades while other longer-term strategies are developed and implemented — the most important being the direct reduction...
The importance of rapid, disturbance-induced losses in carbon management and sequestration
D.D. Breshears, Craig D. Allen
2002, Global Ecology and Biogeography (11) 1-5
Management of terrestrial carbon fluxes is being proposed as a means of increasing the amount of carbon sequestered in the terrestrial biosphere. This approach is generally viewed only as an interim strategy for the coming decades while other longer-term strategies are developed and implemented — the most important being the direct reduction...
A new species of Echinosaura (Gymnophthalmidae) from Ecuador and Colombia with comments on other members of the genus and Teuchocercus keyi
T. H. Fritts, A. Almendariz, S. Samec
2002, Journal of Herpetology (36) 349-355
A new species of the genus Echinosaura is described from the Pacific drainages of northern Ecuador and adjacent Colombia. Evaluation of variation among congeners justifies their recognition as distinct species instead of subspecies as previously proposed. The new lizard occurs in close proximity to Echinosaura horrida and Teuchocercus keyi....
Advanced techniques for modeling avian nest survival
S.J. Dinsmore, Gary C. White, F.L. Knopf
2002, Ecology (83) 3476-3488
Estimation of avian nest survival has traditionally involved simple measures of apparent nest survival or Mayfield constant-nest-survival models. However, these methods do not allow researchers to build models that rigorously assess the importance of a wide range of biological factors that affect nest survival. Models that incorporate greater detail, such...
Influences of spatial and temporal variation on fish-habitat relationships defined by regression quantiles
J. B. Dunham, B.S. Cade, J.W. Terrell
2002, Transactions of the American Fisheries Society (131) 86-98
We used regression quantiles to model potentially limiting relationships between the standing crop of cutthroat trout Oncorhynchus clarki and measures of stream channel morphology. Regression quantile models indicated that variation in fish density was inversely related to the width:depth ratio of streams but not to stream width or depth alone....
Fate and effects of the triazinone herbicide metribuzin in experimental pond mesocosms
J.F. Fairchild, L.C. Sappington
2002, Archives of Environmental Contamination and Toxicology (43) 198-202
Metribuzin is a triazinone herbicide that is widely used for the control of grasses and broad-leaved weeds in soybeans, sugarcane, and numerous other crops. Metribuzin is highly toxic to freshwater macrophytes and algae under laboratory conditions (median plant EC50 = 31 ??g/L; n = 11 species) but has not been...
Accelerated solvent extraction followed by on-line solid-phase extraction coupled to ion trap LC/MS/MS for analysis of benzalkonium chlorides in sediment samples
I. Ferrer, E. T. Furlong
2002, Analytical Chemistry (74) 1275-1280
Benzalkonium chlorides (BACs) were successfully extracted from sediment samples using a new methodology based on accelerated solvent extraction (ASE) followed by an on-line cleanup step. The BACs were detected by liquid chromatography/ion trap mass spectrometry (LC/MS) or tandem mass spectrometry (MS/MS) using an electrospray interface operated in the positive ion...
Adaptive moving mesh methods for simulating one-dimensional groundwater problems with sharp moving fronts
W. Huang, Lingyun Zheng, X. Zhan
2002, International Journal for Numerical Methods in Engineering (54) 1579-1603
Accurate modelling of groundwater flow and transport with sharp moving fronts often involves high computational cost, when a fixed/uniform mesh is used. In this paper, we investigate the modelling of groundwater problems using a particular adaptive mesh method called the moving mesh partial differential equation approach. With this approach, the...
Effects of cottonwood leaf beetle Chrysomela scripta (Coleoptera: Chrysomelidae) on survival and growth of Fremont cottonwood (Populus fremontii) in northwest Colorado
D.C. Andersen, S. M. Nelson
2002, American Midland Naturalist (147) 189-203
Greenhouse and field studies were used to assess the effects of a cottonwood leaf beetle (Chrysomela scripta) outbreak on growth and survivorship of Fremont cottonwood (Populus fremontii) along a segment of the Yampa River in northwestern Colorado. Exposure of greenhouse-reared seedlings to either 1 or 3 larvae reduced...
The nature of the crust under Cayman Trough from gravity
Uri S. ten Brink, D.F. Coleman, William P. Dillon
2002, Marine and Petroleum Geology (19) 971-987
Considerable crustal thickness variations are inferred along Cayman Trough, a slow-spreading ocean basin in the Caribbean Sea, from modeling of the gravity field. The crust to a distance of 50 km from the spreading center is only 2–3 km thick in agreement with dredge and dive results. Crustal thickness increases to ∼5.5 km...
Phylogeography and history of giant Galápagos tortoises
A. Caccone, G. Gentile, J.P. Gibbs, T. H. Fritts, H.L. Snell, J. Betts, J.R. Powell
2002, Evolution (56) 2052-2066
We examined the phylogeography and history of giant Galápagos tortoise populations based on mitochondrial DNA sequence data from 161 individuals from 21 sampling sites representing the 11 currently recognized extant taxa. Molecular clock and geological considerations indicate a founding of the monophyletic Galápagos lineage around 2–3 million years ago, which...
Systematics of Myotis occultus (Chiroptera: Vespertilionidae) inferred from sequences of two mitochondrial genes
A.J. Piaggio, E.W. Valdez, M.A. Bogan, G.S. Spicer
2002, Journal of Mammalogy (83) 386-395
The systematic relationship between Myotis lucifugus carissima and Myotis occultus has been the subject of multiple studies. Although several studies, including a recent allozyme study, concluded that M. occultus is a subspecies of M. lucifugus, this view has not been universally accepted. We reexamined the relationships of these 2 taxa...
Percolation flux and Transport velocity in the unsaturated zone, Yucca Mountain, Nevada
I.C. Yang
2002, Applied Geochemistry (17) 807-817
The percolation flux for borehole USW UZ-14 was calculated from 14C residence times of pore water and water content of cores measured in the laboratory. Transport velocity is calculated from the depth interval between two points divided by the difference in 14C residence times. Two methods were used to calculate...
Public attitudes and knowledge of the black-tailed prairie dog: A common and controversial species
D. Lybecker, B. L. Lamb, P.D. Ponds
2002, BioScience (52) 607-613
No abstract available....
Economic costs of electrical system instability and power outages caused by snakes on the Island of Guam
T. H. Fritts
2002, International Biodeterioration and Biodegradation (49) 93-100
The Brown Tree Snake, Boiga irregularis, is an introduced species on Guam where it causes frequent electrical power outages. The snake's high abundance, its propensity for climbing, and use of disturbed habitats all contribute to interruption of Guam's electrical service and the activities that depend on electrical power. Snakes have...
Taxonomic assessment of the black bear (Ursus americanus) in the eastern United States
M.L. Kennedy, P.K. Kennedy, M.A. Bogan, J.L. Waits
2002, Southwestern Naturalist (47) 335-347
The subspecific status of the Louisiana black bear (Ursus americanus luteolus) and Florida black bear (U. a. floridanus) were assessed using morphologic features to determine their distinctness in relation to one another and to the black bear (U. a. americanus). Forty-four dimensions were recorded from skulls of 125 male and...
Fasting modifies Aroclor 1254 impact on plasma cortisol, glucose and lactate responses to a handling disturbance in Arctic charr
E.H. Jorgensen, M.M. Vijayan, N. Aluru, A.G. Maule
2002, Comparative Biochemistry and Physiology, Part C: Toxicology & Pharmacology (132) 235-245
Integrated effects of polychlorinated biphenyl (PCB) and nutritional status on responses to handling disturbance were investigated in the Arctic charr (Salvelinus alpinus). The fish were orally contaminated with Aroclor 1254 and held either with or without food for 5 months before they were subjected to a 10-min handling disturbance. Food-deprived...
Implications of flood pulse restoration for Populus regeneration on the upper Missouri River
Ken D. Bovee, Michael L. Scott
2002, River Research and Applications (18) 287-298
We developed a mass balance flow model to reconstruct unregulated daily peak flows in the National Wild and Scenic reach of the Missouri River, Montana. Results indicated that although the observed frequency of large peak flows has not changed in the post-dam period, their magnitude has been reduced from 40...
Patterns of rodent abundance on open-space grasslands in relation to suburban edges
C.E. Bock, K.T. Vierling, S.L. Haire, J.D. Boone, W.W. Merkle
2002, Conservation Biology (16) 1653-1658
Relatively little is known about the response of grassland rodent populations to urban and suburban edges. We live-trapped rodents for three summers on 65 3.1-ha grassland plots on open space of the city of Boulder, Colorado, and compared capture rates among species according to habitat type, percentage of the 40...
Gravitational failure of sea cliffs in weakly lithified sediment
M. A. Hampton
2002, Environmental & Engineering Geoscience (8) 175-191
Gravitational failure of sea cliffs eroded into weakly lithified sediment at several sites in California involves episodic stress-release fracturing and cantilevered block falls. The principal variables that influence the gravitational stability are tensional stresses generated during the release of horizontal confining stress and weakening of the sediment with increased saturation...
Antibody responses by chinook salmon (Oncorhynchus tshawytscha) and rainbow trout (Oncorhynchus mykiss) to various protein antigens
S.W. Alcorn, R.J. Pascho
2002, Fish and Shellfish Immunology (13) 327-333
[No abstract available]...
